QUESTION 7

An engineer wants to determine the effectiveness of a safety program. He collects annual loss of hours due to accidents in 12 plants before and after the program was put into operation, and the following summary statistics for the sample difference: mean sample difference in loss of hours due to accidents (between before and after the program was put into operation) = 2.5 and the standard deviation of sample difference = 2.9388. Assuming that the hours difference (between before and after the program was put into operation) is normally distributed, what is the value of the test statistic (round your final answer to two decimal places)?